Low OmniScriptum SRL Low Frequency Radio Range: Low Frequency radio range, Radio navigation, Instrument flight rules, VHF omnidirectional range, Instrument approach, ... pattern, Airway (aviation), Morse code Paperback

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.The Low Frequency radio range, also known as the four-course radio range, LF/MF four-course radio range, A-N radio range, Adcock radio range, or commonly "the range", was the main navigation system used by aircraft for instrument flying in the 1930s and 1940s, until the advent of the VHF omnidirectional range, beginning in the late 1940s. It was used for en route navigation as well as instrument approaches and holds.Based on a network of radio towers which transmitted directional radio signals, the LFR defined specific airways in the sky. Pilots navigated the LFR by listening to a stream of automated "A" and "N" Morse codes. For example, they would turn the aircraft to the right when hearing an "N" stream, to the left when hearing an "A" stream, and fly straight ahead while hearing a steady tone.As the VOR system was phased in around the world, the LFR was gradually phased out, mostly disappearing by the 1970s. There are no remaining operational LFR facilities today. At its maximum deployment, there were nearly 400 LFR stations in the U.S. Alone.